0
$\begingroup$

i am designing an experimental platform to test some 3D printed gears that i am designing. i want to test the durability and what i am looking for is a way to make them wear out fast. i will basically put 2 or 3 gears in series and form a gear train, then run them until they "fail", i am basically cehcing the vibration emitted by each gear, and i currently do it by placing an accelerometer above the shaft supporting the gear itself (above the shaft supporting bearing to be precise)

however the gears reach a point where the vibration increases no more just after running for 15 min.

Any advice on what kind of way to install the accelerometers or other sensors? Or if i should change my DC motor, runs at 24V at 2000RPM but heating up too fast so i have to stop every 10 15 min of run.

$\endgroup$
1
  • $\begingroup$ Some sort of accelerated life test... but you might like to think about what lifespan and load would be "reasonable" for your gears. What are they designed for - working against a high load, or running continuously or start/stop? How long would commercially bought plastic gears last in the same cycle? (I'm just trying to establish if you've thought of these matters yet.) $\endgroup$ – Andy Nov 17 '16 at 15:41
1
$\begingroup$

The difficulty is that 'wearing out' is a bit of a vague concept in engineering and it is not always easy to accelerate wear in a way which is meaningful in the real world.

In many applications running gears under a reasonable approximation of normal operating conditions continuously won't actually take that long to get to a substantial fraction of their design life, bearing in mind that most plastic gear applications tend to run fairly intermittently.

Also as mentioned in the comments you really need to consider what failure mechanisms are most significant. In my experience plastic transmission parts tend to fail through overloading, especially shock and stall type loads long before they wear out as such. Often the failure point is the point at which the gear is attached to the shaft rather than the teeth.

Equally what load do you have on the gear train ? Apart form anything else the no-load torque generated by the gear train is an initial indicator of quality of terms of fit, finish and dimensional tolerances, which is always a concern with 3D printed parts.

With any sort of testing you need to be quite focused on what you are actually trying to measure ad what you intend to learn from the test.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.